Environmental Analysis of Manufacturing Processes

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

The purpose of this project is to develop models and a modeling framework to characterize the environmental performance of manufacturing processes. The project will address eight different processes: milling, grinding, electrical discharge machining, abrasive water jet machining, sand casting, die casting, injection molding, and advanced composites autoclave processing. And, in seven different impact categories: energy, wastes, recycling, hazardous materials, use and contamination of water, emissions to air, and emissions to land, by collecting data and inventories for each case. The centerpiece of this project will be the development of "burdened" equipment level models, and life cycle materials flow models for three key environmental indicators: energy, waste and entropy, and toxic and hazardous materials. With the appropriate data, these models will be able to compare the environmental performance of alternative processes; alternative process plans, and propose new process developments. This information is needed to more clearly focus attention on manufacturing process development needs for a sustainable future. Furthermore, these models will be adapted for use in product design to aid design for the environment. The central theme of this work is to develop an alternative view of manufacturing processes. In addition to being hugely important as value adding, some processes could also be seen as the opposite: as potentially threatening the environment by excessive energy and materials usage, and by mixing and diluting materials such that they cannot be recaptured. This alternative view is necessary to properly evaluate the "sustainability" of existing and future processes. In addition, this work proposes the development of a new process metric - the entropy change -- to assess the potential for recapturing and recycling the materials used. The methodology builds on Shannon's information theory, with several new results derived from a configurationally entropy approach. The work plan involves eight undergraduate theses, under the supervision of a senior graduate student and faculty advisor, and with the collaboration of three additional faculty members with particular expertise in machining processes, casting processes, and toxicity and hazardous materials. The results will be made widely available to the public via a web page and journal articles.